Device for stacking carton blanks and the like



July 13, 1965 o. E. LARSSON 3,194,127

DEVICE FOR STACKING CARTON BLANKS AND THE LIKE Filed Jan. 15, 1963 4 Sheets-Sheet 1 July 13, 1965 o. E. LARSSON 3,194,127

DEVICE FOR STACKING CARTON BLANKS AND THE LIKE Filed Jan. 15, 1963 4 Sheets-Sheet 2 IN VEN TOR.

July 13, 1965 o. E. LARSSON 3,194,127

. DEVICE FOR STACKING CARTON BLANKS AND THE LIKE Filed Jan. 15, 1963 4 Sheets-Sheet 3 July 13, 1965 o. E. LARSSON 3,194,127

DEVICE FOR STACKING CARTON BLANKS AND THE LIKE Filed Jan. 15, 1963 4 Sheets-Sheet 4 United States Patent 3,194,127 DEVICE non s'raorrmo cAnroN AND THE Linn BLANKS 1010f Einar Larsson, Orehro, Sweden, assignor to nnds Verkstader Aktieholag, Sundsvall, Sweden, a corporation of Sweden Filed Jan. 15, 1963, Ser. No. 251,528 Claims priority, application Sweden, .lan. 18, 1962, 555/62. Claims. (Cl. 93-93) in the stack whereby to build up the stack from below and wherein an abutment is provided for limiting the feed of the lowermost blank, an operating device for said abutment being connected to a counting apparatus which is provided with an impulse member and registers the number of car-ton blanks in the stack and, when a predeter- Imined number of blanks have been stacked, emits an impulse for moving the abutment to a releasing position whereupon the stack moves forward on a conveyor.

The main object of the invention is to provide an automatically operating stacking device which is reliable in function and requires minimum supervision. Another object is to provide a device which operates independently of the speed or interval at which the blanks are supplied to the machine. A still further object it is to render possible stacking of underlapping blanks as well as blanks which arrive one by one at the place Where the stack is to be built up. A further object is to provide a stacking device which is not affected in case of interruption of the feed of carton blanks to the stacking place.

In its broadest aspect the invention is characterized in that at least one abutment is adapted immediately upon release of the stack to tend to return to the stopping position under the action of a preferably resilient force which is smaller than the weight of the departing stack.

As a result of the fact that at least one abutment is adapted immediately upon release of the stack to tend to return to the stopping position under the action of a force which is smaller than the Weight of the stack, the next succeeding blank has time to become stopped by the abutment no matter how closely the blanks are succeeding each other, so that building-up of the next stack of correct formation will start immediately. No significant braking is exerted on the departing complete stack, and as soon as the stack has moved past the abutment, the abutment will assumeits normal stopping position for the next following blank. In accordance with a preferred embodiment the impulse member of the counting apparatus is disposed in close proximity to one of the ends of the stack, resulting in that even the last blank of the predetermined number to be comprised in the stack will have arrived at the abutment when the counting apparatus emits an impulse for moving the abutment to the releasing position.

The invention will be described more closely hereinbelow with reference to embodiments thereof illustrated in the drawing. FIGS. 1A and 1B are lateral elevations of the posterior parts of a carton manufacturing machine, the lateral frame beam facing the observer being omitted.

FIGS. 2A and 2B are top views of the machine together with the lateral beams. FIG. 3 is an enlarged lateral elevation of the stop mechanism. FIG. 4 is a diagrammatic lateral elevation of the main parts of another embodiment. FIG. 5 is a perspective view to an enlarged scale of the abutment comprised in the stacking device according to FIG. 4, and FIGS. 6a-c illustrate different positions of the ice abutment, explaining the release of a stack and the return movement of the abutment to the stopping position.

Referring to the embodiment illustrated in FIGS. 1, 2 and 3, carton blanks which have been folded and coated with an adhesive in a preceding part, not shown, of the machine are piled in a stack 14 which is subjected to a suitable treatment forming part of the manufacture and from which the blanks are conveyed to be piled one below the other in a stack 1 at the other end of the machine whereupon the complete stack is delivered from the machine. During the stacking operation the blanks are supplied to the stack from below such that a blank 2 entering the stack lifts the other blanks 1 comprised in the stack whereby to build up the stackfrom below. The advancing movement of the lowermost blank is limited by an abutment 6. The conveyor system is provided with means for imparting to an advancing blank a speed lower than the speed of the next succeeding blank and for providing a difference in the levels of the adjacent ends of the two blanks such that the succeeding blank is partly covered by the preceding blank so as to underlap the preceding blank. To this end, the machine according to the present embodiment is provided with two successive conveyors 7 and 8 comprising endless belts ll5 and 16, respectively, running over various rollers. A further conveyor 9 also comprising endless belts is provided above the previously mentioned conveyors. Between the belts of the conveyors 7 and 3 there are provided upwardly projecting springs 1d which are secured in grooves in edgewise placed rectangular bars 17. The belts 15 of the conveyor 7 extend around rollers 18, 19 and 20 mounted in the stationary frame of the machine and around rollers 21 and 22 mounted on a movable slide 11. The belts 16 of the conveyor 8 extend around rollers 23 and 24 mounted in the stationary frame of the machine, around support rollers 25 one of which is mounted in the movable slide 11, around stretching rollers 26 and 27 and around the rollers 28 and 29 mounted in the movable slide 11. The conveyor 8 also extends around a guide roller 13 and a roller 34 which is mounted in a displaceable part of the stacking device as will be described more closely hereinbelow. The overhead conveyor 9 extends around end rollers 31 and 32 mounted on the movable slide 11 and over rollers 33 and 34 of smaller diameters.

The slide 11 also carries a roller 35 which supports the conveyor 7 below the forward end of the stack 14.

The slide 11 also carries pressure rollers 36 which hold the blanks in contact with the conveyor 7 until the blanks after having been delivered from the stack 14 and after having passed the pressure rollers 36 are lifted by the springs Ill into contact with the conveyor 9 which feeds the blanks forward to the conveyor 8 which undertakes continued transportation.

The conveyors are driven by a suitably placed motor (not shown) which may directly drive the roller 18 of the conveyor 7. The speed of this conveyor is twice the speed of the conveyors 8 and 9 which run at equal speeds. A suitable change speed gear, such as a chain transmission (not shown), transmits the drive from the roller 18 to the roller 23 of the conveyor '3. Another chain transmission may be provided for transmitting the drive from the conveyor 7 to the conveyor 9. The rollers. 22 and 32 of the conveyors 7 and 9, respectively, are mounted on the slide 11 and interconnected by the chain transmission.

In order to enable the machine to be adjusted to different carton sizes, some of the rollers of the conveyors justable via a chain transmission 44, 45, 46 and 4 7 by means of a hand wheel 43 mounted on the lateral beam 410. This arrangement provides for high accuracy of adjustment of the slide 11.

As will best be seen from FIG. 3 the abutment (according to this embodiment) consists of stop plates 6 the height of which above the conveyor 3 slightly exceeds the thickness of two cart-on blanks. The abutment is vertically movable and operated by an electromagnet 49 and a spring 67 the force of which is smaller than the weight of the stack, A counting apparatus 66 receives impulses from a microswitch 48 provided at one end of the stack in close proximity to the abutment. For each blank arriving to the stop plates 6 the microswitch 48 emits an impulse to the counting apparatus. The counting apparatus 66 is in turn connected to the electromagnet 49 the armature 50 of which is via links 51 and 52 connected to the stop plates 6 which project above between the belts 16. The rnicroswitch 48 is a device which only in the middle of the conveyor slightly extends above the level of the conveyor. The abutment 6 and appertaining pants are movable in a carriage (not shown) on the frame of .the machine such that the stacking device, too, is adjustable for different sizes of blanks. The stacking device is adjustable by means of a hand wheel 53 mounted in the lateral beam 40, the movement being transmitted such as by gear wheels 54 which are in mesh with racks 56 mounted on brackets on the frame of the machine.

The belts of the conveyor 8 are deflected by the roller 13 below the plate where the stack is built up. The defiection of the conveyor close to the stacking place is an additional safeguard which ensures the supply of an arriving blank below the other blanks of the stack.

Ahead of the stacking device there is provided a control device 60 in the form of .a photocell which controls the underlap of the blanks advancing on the conveyor 8 and is associated with magnetically operated lifting plates 61. Should the blanks for some reason have ceased to underlap each other, this condition will be registered by the photocell which emits an impulse to the electromagnet 62 which in this case attracts the armature 63 connected to the lifting plates 6-1 by means of a lever 64. As a result, the trailing end of the stack will be lifted and by means of a suitable delay device 69 maintained in lifted position until the blank in consideration can enter the stack from below without interruption of the continuity of the stacking operation. After the abutment 6 has been moved below the conveyor 3 a complete stack 65 advances a short distance on this conveyor and is then delivered therefromsuch as to a roller way or the like, not shown, in the drawing.

Additional details of the mechanism will appear from the following description of the stacking operation. The blanks comprised in the increasing stack are denoted at 1, and a blank entering the stack is denoted at 2. The blanks advancing on the conveyor 8 are denoted at 3, whereas numeral deno-tes the first blank which by means of the springs 10 has been lifted into contact with the overhead conveyor 9. Numeral denotes a blank which is about to be delivered from the stack 14 to the conveyor 7.

The blanks of the stack 14 are discharged therefrom one by one in a conventional manner by the roller 35 supporting the upper run of the convey-or 7 which in cooperation with the pressure rollers 36 advanced the lowermost blank 5, A preceding blank 4 has been lifted by the springs into contact with the overhead conveyor 9 which runs at half the speed of the conveyor 7. Consequently, the blank 5 will be moved under the trailing edge .of the preceding blank 4 so as partly to be covered by the blank 4. In this manner the blanks are caused to underlap each other. From the conveyor 9 the underlapping blanks are moved down onto the conveyor 8 which runs at the same speed as the conveyor 9. The

blanks are then conveyed toward the stacking device and enter the stack from below in a manner such that an entering blank 2 lifts the other blanks 1 of the stack which consequently will be built up from below. The abutment 6 limits the forward movement of the lowermost blank 2. For each blank fed into the stack the microswitch 48 emits an impulse to the counting apparatus 66. When the number of the stacked blanks amounts to a predetermined value the counting apparatus emits an impulse to the electromagnet 49 the iron core of which then attracts the armature 59 connected with the abutment 6 by means of the linkage 51, 52. The abutment is moved down then below the upper run of the conveyor 8 and the complete stack advances on this conveyor and is finally delivered therefrom. The abutment is pulled down against the action of a spring 67 whichimmediatcly returns the abutment into contact with the advancing complete stack which trails on the abutment. The spring force is small enough not to exert a significant braking action on the departing stack. To begin with the stack moves jointly with the entering blank which underlaps the lowermost blank of the complete stack, and the abutment is permitted under the action of the spring 67 to project above the conveyor by a distance corresponding to the height of the arriving blank. As soon as this blank strikes against the abutment the complete stack continues its movement along the conveyor 8 due to frictional engagement between the belts of the conveyor and the lowermost blank of the complete stack. After the trailing edge of the stack has passed the abutment 6 the spring 67 moves the abutment to its full height above the conveyor 8. As previously mentioned, this height cor-responds to the thickness of at least two blanks and it should preferably not exceed the thickness of four to five blanks.

Any failure regarding the underlap of the blanks will be detected and corrected by the photocell 66 which in the manner described above cooperates with the lifting plates 61 via electromagnet 62, armature 63 andlever 64.

A modified embodiment of the invention is illustrated in FIGS. 46 which merely diagrammatically show the essential parts of the device. In this embodiment, the advancing blanks 3 are intended to arrive one by one to the stacking place instead of underlapping each other. Consequently, in this embodiment no overhead conveyor is required. Instead the blanks are fed into the stack from below due to the arrangement of a roller 76 which is provided in close proximity to the stacking place and deflects the conveyor belts 16 in the manner illustrated. Instead of the means effecting an underlap there is provided an arrangement for imparting to an advancing blank immediately ahead of the stacking place a speed higher than the speed of the next succeeding blank. To this end, a plurality of short endless additional belts 71 are arranged between the conveyor belts 16. Similar to the ordinary conveyor belts 16 the additional belts 71 run over rollers 72 and 73, but in contrast to the ordinary belts they run over enlarged-diameter parts 74 and 75 of these rollers. As a result thereof, the upper runs of the additional belts move slightly above and at a higher speed than the ordinary belts. Thus, even if the blanks advance in close succession they will be spaced apart to some extent before arriving at the stack which means an increased reliability in operation.

In addition to the above indicated distinction the device illustrated in FIGS. 4 and 5 differs from the embodiment according to FIGS. 1-3 also in regard to the design and location of the impulse member and the design of the abutment. Instead of the microswitch 48 illustrated in FIGS. 1 and 3 there is provided a photocell 76 which is located at the trailing edge of the stack and connected to a counting apparatus 77. The photocell becomes operative when a blank has been entirely moved into the stack. When the counting apparatus registers the predetermined number of blanks it emits an impulse to a motor 78 which moves the abutment to the releasing position. It is essential that the impulse member, that is the photocell in the present embodiment, be operative when an arriving blank is completely fed into the stack so that even the last blank entering a stack of predetermined height will be registered by the counting apparatus and further advanced together with the stack without the risk of an irregular or non-attractive formation of the stack or interruption of operation.

In the present embodiment the abutment consists of a plurality of spring actuated flaps 81 which are mounted on a horizontal rotatable shaft 80 and are pivotable relative to this shaft and projecting upwards between the belts 16 of the conveyor. As shown in FIGS. 4 and 5 the flaps may be arranged pairwise and in diametrically opposite relation on the shaft. The flaps 81 are mounted for swinging movement about pivots 82 and are urged outwards from the shaft 80 by means of leaf springs 83 the force of which is smaller than the weight of the stack.

The mode of operation of the abutment is as follows. When the counting apparatus 77 has registered the predetermined number of blanks an impulse is emitted to the electric motor '78 which, for instance via the cone belt transmission 79 shown in the drawing, imparts half a revolution to the shaft 80. Of course other means may be used to turn the shaft. The shaft is turned in the forward direction of the conveyor 16, resulting in that the stack is released and moves forward together with the conveyor, FIG. 6d. Immediately after the releasing movement the lower abutment flaps 81 come into contact with the advancing stack and tend to assume the stopping position under the action of the spring 83, FIG. 62). However, since the spring force is smaller than the weight of the stack, the flaps will be retained in lowered positions below the upper run of the conveyor until the stack 1 has passed the abutment. Thereupon the abutment flaps again assume the locking position, FIG. 60, and are ready to stop the next succeeding blank 3. This type of abutment will function also if the blanks are underlapping each other during their movement to the abutment.

The abutment functions in a corresponding manner if the flaps 81 are not arranged pairwise, but individually. In this case the shaft has to be turned through an angle of 360 to the releasing position.

It will be understood, that the invention may be embodied in different manners within the inventive idea. For instance the shaft 80 can be driven to rotate the abutment by friction between the underside of the belts 16 and the shaft 80. Thereby the electrical motor can he left out. The abutment is stopped after being turned an angle of 180 by means of a blocking member, which engages the flaps 81, said blocking member for instance being the electromagnet 49 shown in FIG. 3 and co-operating parts.

What is claimed is:

1. A device for stacking carton blanks and similar stiff blanks in a carton manufacturing machine comprising conveyor means for advancing the carton blanks in one direction; an abutment vertically movable between an upper position and a lower position and adapted when in upper position to limit the advance of the lowermost blank so as to build up at a stacking place a stack from below, one blank entering the stack lifting the other blanks comprised in the stack; an operating device for said abutment; a counting apparatus registering the number of carton blanks fed to the stack, said counting apparatus cooperating with said operating device to transmit to said operating device, after a predetermined number of blanks in the stack has been reached, an impulse efiective for moving said abutment to said lower position thereby releasing the stack to advance past said abutment; and means for resetting said abutment at said upper position immediately upon release of the stack, said resetting means exerting a force on the abutment which force is smaller than the weight of the departing stack.

2. A device according to claim 1, characterized in that the impulse member of the counting apparatus is disposed in close proximity to one end of the stack.

3. A device according to claim 1, characterized in that the height of the abutment above the conveyor when in said upper position equals at least the thickness of two blanks and does not exceed the thickness of four to five blanks.

4. A device according to claim 1, characterized in that the abutment consists of at least one vertically movable member adapted to be lowered to releasing position under action of an electromagnet energized by an impulse from the counting apparatus, said electromagnet being adapted momentarily to attract an iron core connected to the abutment, whereupon the abutment is adapted immediately to tend to return to the upper, blank-limiting position under the action of a suitably located spring.

5. A device according to claim 1, characterized in that the abutment consists of at least one spring-actuated flap which is mounted on a horizontal rotary shaft and pivotal relative to said shaft, and in that the stack is released by forward rotation of the shaft, whereupon the abutment flap again tends to assume its upper, blank-limiting position under the action of the spring.

6. A device according to claim 5, characterized in that two abutment flaps are provided in diametrically opposite relation on the shaft which turns through an angle of during the releasing movement.

7. A device according to claim 5, characterized in that said conveyor means comprises a plurality of spaced, parallel, endiess belts, and in that the shaft carries a plurality of abutment flaps located in the spaces between conveyor belts.

8. A device according to claim 1, characterized in that the conveyor near the stacking place is deflected by at least one roller.

9. A device according to claim 1 wherein the blanks are advanced one by one to the stacking place characterized by means located ahead of the stacking place and adapted to impart to an advancing blank a speed higher than the speed of the next succeeding blank.

10. A device according to claim 9, characterized in that the aforesaid conveyor belts are carried on rollers, and in that said means comprise short endless additional belts arranged between the aforesaid conveyor belts and running over enlarged-diameter parts of the rollers such that said additional belts extend above the plane of the ordinary belts and are advanced at a speed higher than the speed of the ordinary belts.

References Cited by the Examiner UNITED STATES PATENTS 1,868,384 7/32 Greenwood 271-68 X 2,281,089 4/42 Novick 93-62 2,466,544 4/49 Harred 9393.3 X

FRANK E. BAILEY, Primary Examiner. 

1. A DEVICE FOR STACKING CARTON BLANKS AND SIMILAR STIFF BLANKS IN A CARTON MANUFACTURING MACHINE COMPRISING CONVEYOR MEANS FOR ADVANCING THE CARTON BLANKS IN ONE DIRECTION; AN ABUTMENT VERTICALLY MOVABLE BETWEEN AN UPPER POSITION AND A LOWER POSITION AND ADAPTED WHEN IN UPPER POSITION TO LIMIT THE ADVANCE OF THE LOWERMOST BLANK SO AS TO BUILD UP AT A STACKING PLACE A STACK FROM BELOW, ONE BLANK ENTERING THE STACK LIFTING THE OTHER BLANKS COMPRISED IN THE STACK; AN OPERATING DEVICE FOR SAID ABUTMENT; A COUNTING APPARATUS REGISTERING THE NUMBER OF CARTON BLANKS FED TO THE STACK, SAID COUNTING APPARATUS COOPERATING WITH SAID OPERATING DEVICE TO TRANSMIT TO SAID OPERATING DEVICE, AFTER A PREDETERMINED NUMBER OF BLANKS IN THE STACK HAS BEEN REACHED, AN IMPULSE EFFECTIVE FOR MOVING SAID ABUTMENT TO SAID LOWER POSITION THEREBY RELEASING THE STACK TO ADVANCE PAST SAID ABUTMENT; AND MEANS FOR RESETTING SAID ABUTMENT AT SAID UPPER POSITION IMMEDIATELY UPON RELEASE OF THE STACK, SAID RESETTING MEANS EXERTING A FORCE ON THE ABUTMENT WHICH FORCE IS SMALLER THAN THE WEIGHT OF THE DEPARTING STACK. 